A Horticulture Information article from the Wisconsin Master Gardener website, posted 19 Feb 2018

Prairie Dropseed, heterolepis dropseed, , is a warm season grass native to the tallgrass and mixed grass of central North America that is also a popular low-maintenance ornamental landscape in zones 3 to 9. Found mainly on the Great Plains from north to southern Saskatchewan, this long- lived perennial clump-forming grass also occurs less commonly in certain habitats in scattered pockets in the eastern Midwest and Northeast to Quebec. It is native to about the southern half of Wisconsin. It was was named a Plant of Merit by the Missouri Botanical Garden in 2005 and was selected as the Wisconsin Nursery and Landscape Association’s herbaceous perennial of the year 2018. Prairie dropseed, Sporobolus heterolepis, in mid- summer. grow 2-3 feet tall and wide from a fi brous root mass, forming an arching, fountain-like mound of foliage with a fi ne texture. The smooth, medium green linear leaves are very narrow and either fl at or rolled. In fall the dense tufts of foliage turn an attractive golden bronze, often with orange or copper highlights, and resists fl attening by snow so this plant can provide winter interest if not cut back until spring.

In mid- to late summer small pink and brown-tinted fl owers are produced in airy, 3-8 inch long fl ower heads with a narrowly pyramidal silhouette. One or more stout but slender culms develop from the center of each leafy clump. The wiry, open branching panicles terminating in individual are held well above the foliage and add movement in the garden.

Prairie dropseed in late May at Olbrich Botanical Gardens, Madison, WI.

Each has two glumes of diff erent lengths, a lemma, a membranous palea and a fl oret. The wind-pollinated fl orets are highly unusual for a grass, having a fragrance variously described as vaguely reminiscent of , licorice, popcorn or sunfl ower seeds. The fl orets are followed by small, smooth, hardened rounded seeds (technically an achene, a type of fruit, rather than the more Prairie dropseed fl owering (L) and in seed (R). normal caryopsis or grain that most grasses produce) within tan hulls, which drop to the ground when mature – hence the common name of dropseed. such as sparrows and juncos, and other animals, feed on the seeds; Native Americans ground the seed to make fl our. Although it does produce seed it generally does not self-sow freely in gardens.

Grow prairie dropseed in full sun in most types of well-drained soil. Although it prefers dry, rocky soils it does fi ne in heavy clay, too. It tolerates drought, but also periodic inundation so can be used on the upper edges of rain gardens where it doesn’t remain too wet. It has no serious pest problems, is not favored by deer (although it may be grazed), and is tolerant of juglone so it can thrive around black walnuts. Once New growth of prairie dropseed in spring. established it needs little care other than pulling, cutting, or burning the old foliage off in late winter or early spring before new growth begins.

Use prairie dropseed in perennial or mixed borders, naturalistic plantings, meadows, and restored prairies and roadside revegetation. It is a good addition to rain gardens and aids in erosion control. Its fi ne, fl owing appearance is a good contrast to plants with bold foliage or upright form. It makes a great fi ller between many types of herbaceous perennials, but especially those native to prairies, too, such as purple conefl ower ( purpurea), small goldenrods, liatris, blackeyed Susan (Rudbeckia fulgida var. fulgida), and butterfl y weed (Asclepias tuberosa). Planted in large masses it can be used as a tall ground cover or Prairie dropseed combined with fall-blooming sedums and can be used to create a distinctive border, but it alliums. can also be used as an accent specimen plant. It is particularly nice when positioned so the fl ower and seed heads are backlit. It can be the dominant plant in a “matrix planting” where a single , or handful of species form a matrix into which other plants are blended. In its native habitats it is commonly associated with little bluestem (Schizachyrium scoparium), big bluestem (Andropogon gerardii var. gerardii), grama grasses ( spp.), panic grass (Panicum spp.), Indiangrass (), leadplant (Amorpha canescens), green milkweed (Asclepias viridifl ora), coreopsis (Coreopsis spp.), purple sorrel (Oxalis violacea), phlox (Phlox spp.), and yellow cone Prairie dropseed with purple Verbena bonariensis fl ower (Ratibida pinnata) among other plants. and other ornamental plants. Although prairie dropseed can be grown from seed, it is slow growing, taking about 4 years to reach blooming size so is often started from plugs (in prairie restoration) or divisions (in gardens). If growing from seed, sow outdoors in fall or stratify in dry soil for 10 weeks if planting indoors in spring. Divisions, taken in spring once growth resumes, can take a long time to establish, but clumps rarely require dividing and are very dense and diffi cult to divide.

Generally only the species is available, however, plantsman Roy Diblik of Northwind Perennial Farms in Burlington, WI discovered a dwarf selection in 1994 in the Kettle Moraine area and introduced it as the cultivar ‘Tara’.

– Susan Mahr, University of Wisconsin - Madison Sporobolis heterolepis ‘Tara’ at Olbrich Botanical Gardens, Madison, WI.

Additional Information:

Sporobolus heterolepis – on the Missouri Botanic Garden’s Kemper Center for Home Gardening website at http://www.missouribotanicalgarden.org/PlantFinder/PlantFinderDetails. aspx?kempercode=f680 Prairie Dropseed – on the Illinois Wildfl owers website at http://www.illinoiswildfl owers.info/grasses/ plants/pr_dropseed.htm Sporobolus heterolepis – on the Lady Johnson Wildfl ower Center website at https://www. wildfl ower.org/plants/result.php?id_plant=SPHE